Toner cartridge for image forming device including flight with magnetic particles to generate a magnetic field

ABSTRACT

A toner cartridge for an image forming device includes a body for holding toner and a flight. The flight contains magnetic particles and is configured to guide movement of a magnetic field sensor. The magnetic particles generate a magnetic field that the sensor reads. Other systems and methods are disclosed.

CROSS REFERENCES TO RELATED APPLICATIONS

This application claims priority as a continuation of U.S. patentapplication Ser. No. 15/227,637, filed Aug. 3, 2016.

BACKGROUND 1. Field of the Disclosure

The present disclosure relates generally to anti-counterfeit systems andmore particularly to physical unclonable functions.

2. Description of the Related Art

Counterfeit printer supplies, such as toner bottles, are a problem forconsumers. Counterfeit supplies may perform poorly and may damageprinters. Printer manufacturers use authentication systems to detercounterfeiters. Physical unclonable functions (PUF) are a type ofauthentication system that implements a physical one-way function.Ideally, a PUF cannot be identically replicated and thus is difficult tocounterfeit. Thus, it is advantageous to maximize the difficulty ofreplicating a PUF to deter counterfeiters. It is also advantageous forthe PUF and PUF reader to be low cost.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification, illustrate several aspects of the present disclosure, andtogether with the description serve to explain the principles of thepresent disclosure.

FIG. 1 is a block diagram of an imaging system including an imageforming device according to one example embodiment.

FIG. 2 is a top view of a helical PUF.

FIG. 3 is a side view of a PUF reader.

FIG. 4 is a top view of a supply item for an imaging device having ahelical PUF.

FIG. 5 is a graph of magnetic field intensity above a helical flight.

FIG. 6 is example values for generating a digital signature.

FIG. 7 is a top view of a helical PUF.

FIG. 8 is a section view of a helical PUF.

FIG. 9 is a section view of a helical PUF.

FIG. 10, FIG. 11, and FIG. 12 are top views of a helical PUF.

FIG. 13 is a top view of a helical PUF.

FIG. 14 is a top view of a helical PUF.

FIG. 15 is a top view of a supply item for an imaging device having ahelical PUF.

FIG. 16 is a flowchart of a method of manufacturing a supply item for animaging device.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanyingdrawings where like numerals represent like elements. The embodimentsare described in sufficient detail to enable those skilled in the art topractice the present disclosure. It is to be understood that otherembodiments may be utilized and that process, electrical, and mechanicalchanges, etc., may be made without departing from the scope of thepresent disclosure. Examples merely typify possible variations. Portionsand features of some embodiments may be included in or substituted forthose of others. The following description, therefore, is not to betaken in a limiting sense and the scope of the present disclosure isdefined only by the appended claims and their equivalents.

Referring to the drawings and particularly to FIG. 1, there is shown ablock diagram depiction of an imaging system 50 according to one exampleembodiment. Imaging system 50 includes an image forming device 100 and acomputer 60. Image forming device 100 communicates with computer 60 viaa communications link 70. As used herein, the term “communications link”generally refers to any structure that facilitates electroniccommunication between multiple components and may operate using wired orwireless technology and may include communications over the Internet.

In the example embodiment shown in FIG. 1, image forming device 100 is amultifunction device (sometimes referred to as an all-in-one (AIO)device) that includes a controller 102, a user interface 104, a printengine 110, a laser scan unit (LSU) 112, one or more toner bottles orcartridges 200, one or more imaging units 300, a fuser 120, a media feedsystem 130 and media input tray 140, and a scanner system 150. Imageforming device 100 may communicate with computer 60 via a standardcommunication protocol, such as, for example, universal serial bus(USB), Ethernet or IEEE 802.xx. Image forming device 100 may be, forexample, an electrophotographic printer/copier including an integratedscanner system 150 or a standalone electrophotographic printer.

Controller 102 includes a processor unit and associated memory 103 andmay be formed as one or more Application Specific Integrated Circuits(ASICs). Memory 103 may be any volatile or non-volatile memory orcombination thereof such as, for example, random access memory (RAM),read only memory (ROM), flash memory and/or non-volatile RAM (NVRAM).Alternatively, memory 103 may be in the form of a separate electronicmemory (e.g., RAM, ROM, and/or NVRAM), a hard drive, a CD or DVD drive,or any memory device convenient for use with controller 102. Controller102 may be, for example, a combined printer and scanner controller.

In the example embodiment illustrated, controller 102 communicates withprint engine 110 via a communications link 160. Controller 102communicates with imaging unit(s) 300 and processing circuitry 301 oneach imaging unit 300 via communications link(s) 161. Controller 102communicates with toner cartridge(s) 200 and non-volatile memory 201 oneach toner cartridge 200 via communications link(s) 162. Controller 102communicates with fuser 120 and processing circuitry 121 thereon via acommunications link 163. Controller 102 communicates with media feedsystem 130 via a communications link 164. Controller 102 communicateswith scanner system 150 via a communications link 165. User interface104 is communicatively coupled to controller 102 via a communicationslink 166. Processing circuitry 121 and 301 may include a processor andassociated memory such as RAM. ROM, and/or non-volatile memory and mayprovide authentication functions, safety and operational interlocks,operating parameters and usage information related to fuser 120, tonercartridge(s) 200) and imaging unit(s) 300, respectively. Controller 102processes print and scan data and operates print engine 110 duringprinting and scanner system 150 during scanning.

Computer 60, which is optional, may be, for example, a personalcomputer, including memory 62, such as RAM, ROM, and/or NVRAM, an inputdevice 64, such as a keyboard and/or a mouse, and a display monitor 66.Computer 60 also includes a processor, input/output (I/O) interfaces,and may include at least one mass data storage device, such as a harddrive, a CD-ROM and/or a DVD unit (not shown). Computer 60 may also be adevice capable of communicating with image forming device 100 other thana personal computer such as, for example, a tablet computer, asmartphone, or other electronic device.

In the example embodiment illustrated, computer 60 includes in itsmemory a software program including program instructions that functionas an imaging driver 68, e.g., printer/scanner driver software, forimage forming device 100. Imaging driver 68 is in communication withcontroller 102 of image forming device 100 via communications link 70.Imaging driver 68 facilitates communication between image forming device100 and computer 60. One aspect of imaging driver 68 may be, forexample, to provide formatted print data to image forming device 100,and more particularly to print engine 110, to print an image. Anotheraspect of imaging driver 68 may be, for example, to facilitate thecollection of scanned data from scanner system 150.

In some circumstances, it may be desirable to operate image formingdevice 100 in a standalone mode. In the standalone mode, image formingdevice 100 is capable of functioning without computer 60. Accordingly,all or a portion of imaging driver 68, or a similar driver, may belocated in controller 102 of image forming device 100 so as toaccommodate printing and/or scanning functionality when operating in thestandalone mode.

Several components of the image forming device 100 are user replaceablee.g. toner cartridge 200, fuser 120, and imaging unit 300. It isadvantageous to prevent counterfeiting these user replaceablecomponents. A PUF 202 may be attached to the toner cartridge 200 toprevent counterfeiting as described below. A PUF reader 203 may beintegrated into the image forming device 100 to verify the authenticityof the PUF 202. Data related to the PUF 202 may reside in non-volatilememory 201.

FIG. 2 shows PUF 202 with a flight 210 formed as a helical flightextending around a shaft 212. The helical flight 210 and the shaft 212may be coextensive and formed together as one integrated part.Alternatively, they may be two separate parts attached together. The PUF202 has a pair of cylindrical supports 214, 216 that extend laterallyfrom each end of the PUF 202. In operation, the PUF 202 rotates about anaxis of rotation 218. The cylindrical supports 214, 216, the shaft 212,and the helical flight 210 are centered on the axis of rotation. Theflight 210 may be referred to as an auger, a spiral flight or other.

The helical flight 210 contains magnetized particles that generate amagnetic field, including a magnetic field above the top surface 220 ofthe helical flight 210. The magnetized particles are, for example,flakes of an alloy of neodymium, iron and boron (NdFeB). The shaft 212may contain magnetized particles to add complexity to the magneticfield. The PUF 202 may be located on a body of a supply item for animage forming device such as, for example, toner cartridge 200. When thetoner cartridge 200 is located in the image forming device 100, the PUF202 interfaces with the PUF reader 203, which contains a magnetic fieldsensor 222 mounted to a printed circuit board (PCB) 224. The PCB 224also has a locating pin 226.

FIG. 3 shows a side view of the PUF reader 203, including the magneticfield sensor 222, the PCB 224, and the locating pin 226. The locatingpin 226 is taller than the magnetic field sensor 222. When the PUFreader 203 is engaged with the PUF 202, the flight guides movement ofthe reader. Preferably, the locating pin 226 rides on the shaft 212 andthe magnetic field sensor 222 is located above the helical flight 210without contacting the helical flight 210. The locating pin material andshape may be selected to minimize the drag against the PUF 202.Alternatively, the magnetic field sensor 222 may ride on the helicalflight 210. The PUF reader 203 is mounted such that it is free to movein a compliance direction 310 that is preferably radial to the axis ofrotation 218. Preferably, the PUF reader 203 is biased by a springagainst the shaft 212. This mounting compliance helps accommodatemechanical and positional tolerances between the PUF 202 and the PUFreader 203, which improves reliability and reduces manufacturing costs.The magnetic field sensor 222 may make measurements radial to the axisof rotation 218 i.e. parallel to the compliance direction 310. Themagnetic field sensor 222 may make measurements parallel to the axis ofrotation 218 i.e. perpendicular to the compliance direction 310. Themagnetic field sensor 222 may make measurements in three orthogonaldirections.

The locating pin 226 is biased against a side surface 230 of the helicalflight 210. The magnetic field sensor 222 follows a measurement path 228along a section of the helical flight 210. The measurement path 228 isat a fixed distance from the side surface 230. The distance between themagnetic field sensor 222 and the locating pin 226 as well as the anglebetween the PUF reader 203 and the helical flight 210 determines thefixed distance.

In operating, the PUF reader 203 is moved parallel to the axis ofrotation 218. The locating pin 226 pushes against the side surface 230,causing the PUF 202 to rotate about the axis of rotation 218. Since thelocating pin 226 remains in contact with the side surface 230, thepositional accuracy of the measurement path 228 remains steadfast alongan extent of the flight. This is important, since shifting themeasurement path 228 laterally by a small amount may radically changethe magnetic field seen by the magnetic field sensor 222. The helicalPUF 202 is superior to a linear PUF since translation of the PUF readerto read the PUF also maintains the position of the PUF reader relativeto the PUF. Preferably, the magnetic field sensor 222 and locating pin226 are aligned parallel to the axis of rotation 218 to prevent acounterfeiter from replacing the helical PUF 202 with a linear PUF sincethe locating pin 226 would raise the magnetic field sensor 222 too farabove the linear PUF.

The helical flight 210 has a helix angle 232. Preferably, the helixangle 232 is between thirty degrees and sixty degrees inclusive. If thehelix angle 232 is less than thirty degrees the PUF 202 may bind andfail to rotate. If the helix angle 232 is more than sixty degrees thePUF 202 may fail to maintain contact between the locating pin 226 andthe side surface 230. Preferably, the helix angle 232 is less than sixtydegrees so the maximum helical flight length may be provided for a givenPUF length, since a longer PUF is harder to duplicate than is a shorterPUF.

FIG. 4 shows the helical PUF 202 located on a supply item for an imagingdevice e.g. toner cartridge 200. The toner cartridge 200 has a body 410for holding toner. The helical PUF 202 is rotatably mounted to the bodyby bearings 412, 414 that encircle the cylindrical supports 214, 216.Non-volatile memory 201 is also located on the body 410 and is mountedto a PCB 416 having a column of electrical contact pads 418. Thenon-volatile memory 201 may contain an array of numbers corresponding tothe intensity of the magnetic field along a section of the measurementpath 228. The non-volatile memory 201 may also contain a digitalsignature generated from the array of numbers. To clone the tonercartridge, a counterfeiter must either duplicate a genuine helical PUFand also duplicate the accompanying non-volatile memory, which isdifficult, or the counterfeiter must create a counterfeit helical PUFand also create a properly signed array of measurements corresponding tothe counterfeit PUF, which is also difficult. Thus, the toner cartridge200 is protected from counterfeiting.

FIG. 5 shows a graph 500) of the intensity 510 of an example magneticfield along a section of the measurement path 228. An array of numbers512 corresponds to the magnetic field intensity measured at regularintervals along the path, as shown by dotted lines 514 on the graph.Preferably, the array of numbers 512 are integers to simplifyprocessing. Alternatively, the array of numbers may be, for example,floating point. The numbers in FIG. 5 and FIG. 6 are in hexadecimalformat.

FIG. 6 shows an example of generating a digital signature from the arrayof numbers 512. Other algorithms for generating a digital signature areknown in the art. The digital signature is used by the controller 102 toverify that the PUF data in the non-volatile memory is authentic. Thetoner cartridge's serial number 610 and the array of numbers 512 arecombined to form a message 612. Preferably, the message is encrypted.Alternatively, the message may be unencrypted. For this example, AES-CBCis used (see, for example, RFC3602 “The AES-CBC Cipher Algorithm and ItsUse with IPsec” published by The Internet Society (2003), and NIST(National Institute of Standards) documents FIPS-197 (for AES) and toSP800-38A (for CBC)). The AES key 614 and CBC Initialization Vector (IV)616 are used as is known in the art to generate the encrypted message618. In this example, to sign the encrypted message 618 first themessage is hashed then the hash is encrypted with the private key 620 ofan asymmetric key pair that includes a public key 622. This example usesthe SHA-512 hashing algorithm and Elliptic Curve Digital SignatureAlgorithm (ECDSA) utilizing a P-512 curve key, as is known in the art.Other algorithms are known in the art. The SHA-512 hash 624 of theencrypted message 618 is used to generate an ECDSA P-512 digitalsignature 626. The signature 626 and encrypted message 618 are stored inthe non-volatile memory 201. The image forming device 100 may use thearray of numbers 512 in the encrypted message 618 to verify theauthenticity of the helical PUF 202, and the image forming device 100may use the digital signature 626 to verify the authenticity of thearray of numbers 512. In this way, the image forming device 100 mayverify the authenticity of the toner cartridge 200.

FIG. 7 shows the helical PUF 202. FIG. 8 shows a section view of thehelical PUF 202 cut along cross-section line 710. In this example, theshaft 212 and the helical flight 210 are two separate parts attachedtogether. The helical flight 210 contains magnetized particles 810, 812that generate a magnetic field above the top surface 220 and adjacent tothe side surface 230. The helical flight 210 has a rectangular crosssection. The side surface 230 is planar which improves the locatingtolerance of the locating pin 226. FIG. 9 shows an alternate embodimentwith the helical flight 210 having a semi-circular cross section. Theside surface 230 is curved which reduces the friction between thelocating pin 226 and the helical flight 210. Other helical flight crosssections may be used e.g. triangular, etc.

FIG. 10 shows an alternate embodiment of a helical PUF 1002. The helicalflight is a shaft 1010 that has a helical channel 1050 wrapped aroundthe shaft 1010. The shaft 1010 contains magnetized particles thatgenerate a magnetic field above the shaft 1010 having varying intensity.The helical channel 1050 has a first side surface 1030. The helical PUF1002 is configured to rotate about an axis of rotation 1018. A pair ofcylindrical supports 1014, 1016, the shaft 1010, and the helical channel1015 are centered on the axis of rotation.

In operation, the locating pin 226 of the PUF reader 203 pushes againstthe first side surface 1030, causing the magnetic field sensor 222 tofollow a first measurement path 1028 along a section of the length ofthe helical channel 1050. The first measurement path 1028 is at a firstfixed distance 1052 from the side surface 1030. In this example, the PUFreader 203 is moving from right to left. FIG. 11 shows the helical PUF1002 while the PUF reader 203 is moving from left to right. The locatingpin 226 pushes against a second side surface 1054 of the helical channel1050, causing the magnetic field sensor 222 to follow a secondmeasurement path 1129 located a second fixed distance 1156 from thefirst side surface 1030. The second fixed distance 1156 is shorter thanthe first fixed distance 1052. Thus, a single helical PUF 1002 with asingle PUF reader 203 may measure two different measurement paths byalternating the direction of travel of the PUF reader 203. This makes itmore difficult to counterfeit the helical PUF 1002, since twomeasurement paths must be duplicated. In operation, preferably the PUFreader 203 initially moves by at least the helical channel pitch 1157 tobe sure the locating pin 226 falls into the helical channel. Then, thePUF reader 203 moves in the opposite direction at least a distance equalto the helical channel pitch since the actuator moving the PUF reader203 will be designed to travel at least that distance.

FIG. 12 shows an alternate PUF reader 1203 that may measure along twomeasurement paths 1028, 1228 simultaneously. The PUF reader 1203 has twomagnetic field sensors 1222, 1223 located on opposite sides of alocating pin 1226.

FIG. 13 shows an alternate embodiment of a helical PUF 1302. A helicalchannel 1350 wraps around a shaft having magnetized particles. Thehelical channel 1350 terminates in a stop 1366 at the left end and asecond stop 1368 at the right end 1368. In operation, the PUF reader 203may be moved laterally along the helical PUF 1302 from left to rightuntil the locating pin 226 hits stop 1368. The controller 102 may detectthis event by monitoring drive current to a motor that moves the PUFreader 203. When this event is detected, the controller 102 knows thePUF reader 203 is at a home position relative to the PUF 1302. Knowingthis helps the controller 102 to align data measured along a measurementpath with data stored in the toner cartridge non-volatile memory. Asecond home position may be at stop 1366.

FIG. 14 shows an alternate PUF reader 1472 that measures a magneticfield adjacent to the side surface 1030. The PUF reader 1472 has amagnetic field sensor 1470 that measures the intensity of the magneticfield normal to the side surface 1030 and parallel to the side surface.The PUF reader 1472 touches the side surface 1030 with a pair of spacers1474, 1476. In operation, the PUF reader 1472 is moved parallel to theaxis of rotation to measure a section of the length of the helicalchannel 1050.

FIG. 15 shows an alternate embodiment of a supply item for an imagingdevice e.g. toner cartridge 1500. The toner cartridge 1500 has a body1505 for holding toner. A helical PUF 1502 is configured to slidelaterally along a drive shaft 1580 located on an axis of rotation 1518of the helical PUF 1502. The drive shaft 1580 may be turned by a drivegear 1584 that is coupled to a motor located in the imaging device 100.The helical PUF 1502 is rotatably mounted to the body 1505 by bearings1512, 1515. The drive shaft 1580 has a flat area 1582 which gives thedrive shaft 1580 a “D” shaped cross section i.e. the drive shaft 1580 isa D-shaft. The helical PUF 1502 has a “D” shaped hole around the axis ofrotation 1518 that is larger than the cross section of the drive shaft1580. Thus, the helical PUF 1502 will rotate when the drive shaft 1580is rotated and the helical PUF 1502 is free to slide laterally along thedrive shaft 1580 parallel to the axis of rotation.

The helical PUF 1502 has a helical flight 1510 and a helical channel1550. The helical flight 1510 contains magnetized particles thatgenerate a magnetic field adjacent to the helical flight 1510. A PUFreader 1503, located in the imaging device 100, has a locating pin 1526and a magnetic field sensor 1522. The PUF reader 1503 is fixedly mountedto the imaging device 100. In operation, rotation of the drive shaft1580 causes a side surface of the helical flight 1510 to contact thelocating pin 1526, which causes the helical PUF 1502 to slide laterallyalong the drive shaft 1580. The magnetic field sensor 1522 reads theintensity of the magnetic field along a section of the length of thehelical flight, and the controller 102 compares the measured field to anarray of numbers stored in a non-volatile memory 1501 mounted to thebody 1505. Alternatively, the magnetic field sensor may be located inthe helical channel 1550 and measure along a side surface. Thisembodiment simplifies mounting the PUF reader 1503 since the PUF reader1503 does not require a mechanism to translate laterally along thehelical PUF 1502.

Preferably, the locating pin 1526 is positioned offset from the axis ofrotation 1518 to provide a torque on the helical PUF 1502 relative tothe drive shaft 1580. This torque increases the friction between thehelical PUF 1502 and the drive shaft 1580 to insure continuous contactbetween the locating pin 1526 and the helical flight 1510.

1 FIG. 16 shows an example embodiment of a method of manufacturing asupply item for an imaging device according to one embodiment. Method1600 creates a supply item that is difficult to counterfeit.

At block 1610, a body is obtained. The body may be, for example,suitable to hold toner for an imaging device. At block 1612, a helicalauger is obtained. The helical auger has a spiral flight havingmagnetized particles generating a magnetic field above the flight havinga varying intensity. At block 1614, a non-volatile memory device isobtained. At block 1616, the non-volatile memory device is attached tothe body. At block 1618, the helical auger is rotatably attached to thebody.

At block 1620, an array of measurements are created by measuring theintensity of the magnetic field along a section of the spiral flight. Atblock 1622, a digital signature is generated from the array ofmeasurements. At block 1624, the array of measurements is stored in thenon-volatile memory device, and the digital signature is stored in thenon-volatile memory device. These blocks may be performed in alternateorders.

The foregoing description illustrates various aspects and examples ofthe present disclosure. It is not intended to be exhaustive. Rather, itis chosen to illustrate the principles of the present disclosure and itspractical application to enable one of ordinary skill in the art toutilize the present disclosure, including its various modifications thatnaturally follow. All modifications and variations are contemplatedwithin the scope of the present disclosure as determined by the appendedclaims. Relatively apparent modifications include combining one or morefeatures of various embodiments with features of other embodiments.

The invention claimed is:
 1. A toner cartridge for an image formingdevice, comprising: a body for holding toner for use in the imageforming device; and a flight, all components of which are located on theoutside of the body for guiding a magnetic field sensor, the flightcontaining a plurality of magnetic particles, wherein a magnetic fieldintensity of the plurality of magnetic particles varies along a path ofthe magnetic field sensor.
 2. The toner cartridge of claim 1, whereinthe plurality of magnetic particles include flakes of an alloy ofneodymium, iron and boron (NdFeB).
 3. The toner cartridge of claim 1,wherein the flight is a helical flight.
 4. The toner cartridge of claim1, wherein the flight has a top surface and the magnetic particlesgenerate a magnetic field extending above the top surface.
 5. The tonercartridge of claim 1, wherein the flight has a rectangular cross sectionincluding a generally planar side surface.
 6. The toner cartridge ofclaim 1, wherein the flight has a semi-circular cross section includinga curved side surface.
 7. The toner cartridge of claim 1, furtherincluding a shaft, the flight extending around the shaft.
 8. The tonercartridge of claim 7, wherein the shaft and the flight are coextensiveas one integral part.
 9. The toner cartridge of claim 7, wherein theshaft and the flight are two separate parts attached together.
 10. Thetoner cartridge of claim 1, further including a non-volatile memorycontaining a serial number of the body.
 11. The toner cartridge of claim1, further including a non-volatile memory containing an array ofnumbers corresponding to an intensity of a magnetic field generated bythe plurality of magnetic particles measured at a plurality of locationsalong an extent of the flight.
 12. The toner cartridge of claim 1,wherein the flight is configured to rotate about an axis of rotation.13. The toner cartridge of claim 12, further including a shaft centeredon the axis of rotation.
 14. The toner cartridge of claim 13, whereinthe flight extends from a surface of the shaft.
 15. The toner cartridgeof claim 13, wherein the flight is a channel extending into the shaft.16. The toner cartridge of claim 12, wherein the shaft further includesadditional pluralities of magnetic particles.
 17. The toner cartridge ofclaim 12, wherein the flight is angled relative to the axis of rotationin a range of about thirty degrees to sixty degrees.
 18. A tonercartridge for an image forming device, comprising: a body for holdingtoner for use in the image forming device; a flight, all components ofwhich are located on the outside of the body for guiding movement of amagnetic field sensor, wherein the flight contains a plurality ofmagnetic particles that generate a magnetic field that the magneticfield sensor reads, further wherein a magnetic field intensity of theplurality of magnetic particles varies along a path of the magneticfield sensor; and a shaft, the flight being configured to rotate aboutan axis of rotation and the shaft extends along the axis of rotation.19. The toner cartridge of claim 18, wherein the flight has a topsurface and the magnetic field extends above the top surface.
 20. Thetoner cartridge of claim 18, further including a non-volatile memorycontaining numbers corresponding to an intensity of the magnetic fieldgenerated by the plurality of magnetic particles measured at a pluralityof locations along an extent of the flight.